Eh, this is where I begin to quibble. I'd say having things in common is the very premise for successful communication. (It doesn't necessarily mean you have to like the person. Say I can communicate quite well with Seven because we've had similar experiences in life, similar cultures that we grew up in etc, but I doubt he likes me.

) Also, physical attraction is pretty damn relative. Have you ever had that feeling after you split up with someone because of something negative that happened, and you started seeing them in a different light, suddenly asking yourself "what was it that I saw in her anyway"? I think attraction has a lot to do with how you get along with the person to begin with, it's in no way objective.
Btw your courtship with Sergio is really touching